The Environmental Protection Agency (EPA), in a final agency action pursuant to the Clean Air Act, as amended, 42 U.S.C. Sec. 7401, et seq., has approved, conditionally approved, and disapproved various provisions of the State Implementation Plan adopted by the State of Michigan in an effort to comport with nationally-required air quality standards. Petitioner National Steel Corporation, Great Lakes Steel Division, is seeking review of that action. For the reasons detailed below, we find that the EPA administrator neither overstepped the bounds of her authority nor made decisions which were "arbitrary and capricious, an abuse of discretion, or otherwise not in accordance with law." 5 U.S.C. Sec. 706(2)(A) (1970). Accordingly, we affirm the EPA final action.

* A combined state and federal program to control air pollution was formulated in 1970 through various amendments to the Clean Air Act, 42 U.S.C. Sec. 7401, et seq. (the Act). Pursuant to the mandates of Secs. 108 and 109 of the Act, the EPA promulgated national ambient air quality standards (NAAQS) for a variety of pollutants. The standards relevant to the case before us are those governing total suspended particulates in the air.1 The limitations on particulate matter were set at levels deemed necessary to protect the public health and welfare.

The states were given the primary responsibility for achieving these air quality levels and, absent special circumstances, were required to do so by 1975. In keeping with this responsibility, the states were required, under Sec. 110 of the Act to develop state implementation plans (SIPs) providing for the attainment and maintenance of the federal standards. The administrator was required to approve any state plan satisfying the criteria detailed in Sec. 110(a)(2)(A)-(H).2 See Union Electric Co. v. EPA, 427 U.S. 246, 250, 96 S. Ct. 2518, 2522, 49 L. Ed. 2d 474 (1975). If, however, a state either failed to submit a plan, submitted an inadequate one, or failed to revise its plan when required to do so, the administrator was to promulgate a federal plan aimed at achieving the appropriate air quality in that state. 42 U.S.C. Sec. 7410(c).

As of 1975, portions of many states had failed to achieve the national standards, despite the existence of previously approved SIPs. The Act was amended in 1977 in order to deal with these "nonattainment areas". Under the amendment (now Part D of Title I of the Act), states are required to submit revisions to their SIPS demonstrating that the NAAQS will be attained "as expeditiously as practicable," though no later than the end of the 1982 calendar year.

These Part D plans must meet the requirements of Sec. 172(b) of the Act. In pertinent part, Sec. 172 provides that the SIP shall, inter alia:

(2) provide for the implementation of all reasonably available control measures as expeditiously as practicable;

(3) require, in the interim, reasonable further progress (as defined in Section 171(11)) including such reduction in emissions from existing sources in the area as may be obtained through the adoption, at a minimum, of reasonably available control technology (RACT).

42 U.S.C. Sec. 7502(b).

In an effort to, at minimum, prevent the exacerbation of existing nonattainment problems, Congress required all SIPs to provide for a moratorium on the construction of new sources of pollutants, or on the modification of existing ones, unless the state had an approved Part D plan by July 1, 1979. Michigan did not have an approved plan by the deadline and the EPA imposed the required moratorium.

In determining the requirements for an acceptable Part D plan, the EPA addressed a number of practical concerns. Most relevant to this case was the stance the EPA took with regard to fugitive emissions--i.e., matter having a negative impact on air quality which does not originate from a stack or vent, including, but not limited to, dust from ore storage piles, road dust and dust from nonindustrial urban sources. Since these emissions could easily play a significant role in nonattainment, and are so difficult to measure or control, it was clear that attainment would be difficult to demonstrate. The EPA recognized the possibility that a state might require RACT and still be unable to demonstrate attainment because of these immeasurables.

To avoid this problem, the EPA established alternative criteria for determining whether a state's plan was acceptable. First, the EPA decided to approve state plans where the state mandated RACT on all major stationary sources, met the other requirements of Sec. 172,3 and agreed to submit a schedule of measures to control fugitive sources of matter. Alternatively, the EPA decided to approve state plans which could demonstrate attainment "as expeditiously as practicable" without requiring RACT.

In order to assess whether a particular Part D SIP revision reflected RACT, EPA amassed data indicating levels of performance achieved by application of control technology at particulate sources. A particularly large amount of data was compiled with regard to iron and steel sources. On September 8, 1980, the EPA announced that it had compiled a "guidance" document summarizing that data. The EPA indicated that it would combine this data with that presented by the state and then approve, disapprove or conditionally approve4 all elements of the SIPs submitted.

Applying this statutory and regulatory scheme, the EPA approved Michigan's original SIP in 1972. In 1978, however, the administrator designated certain areas of Michigan, including Detroit, "nonattainment areas" for particulate matter and various chemicals. On April 25, 1979, Michigan submitted its required Part D revisions for these areas.

On May 22, 1981, the EPA published a notice of final rulemaking with regard to Michigan's Part D revisions for those nonattainment areas containing iron and steel sources. The overall strategy for emission and particulate matter control in these source areas was conditionally approved upon the state's commitment to adopt regulations which the EPA felt reflected RACT. The specific provisions of the SIP were approved, conditionally approved and/or disapproved as follows:

(1) EPA disapproved the state emission limitations for blast furnaces,5 heating and reheating furnaces,6 and sintering plants7 because data contained in EPA's RACT materials indicated that more stringent limitations would be achievable.

(2) EPA conditionally approved the rule for pushing emissions from slot-type coke ovens.8(3) EPA conditionally approved the rule for standpipe assembly emissions during the coke cycle from slot-type coke ovens.9

(4) EPA conditionally approved the emission limitations for coke oven quench towers.10

(5) EPA conditionally approved the emission limitation for scarfing.11

It is this final rulemaking with regard to iron and steel sources which Great Lakes Steel contests.

This Court's standard of review with regard to EPA action concerning a SIP is an extremely narrow one. The standards set out in the Administrative Procedure Act (APA), 5 U.S.C. Sec. 706, are controlling. See Citizens to Preserve Overton Park v. Volpe, 401 U.S. 402, 413, 91 S. Ct. 814, 822, 28 L. Ed. 2d 136 (1971); South Terminal Corp. v. Environmental Protection Agency, 504 F.2d 646, 655 (1st Cir.1974). Those APA guidelines require us to determine whether the EPA followed the proper lawful procedures and acted within its statutory authority when it promulgated its final rulemaking and whether that rulemaking is constitutional. If so, we may set aside the EPA actions only if we find that the actual choices made were "arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law." 5 U.S.C. Sec. 706(2)(A).

In Northern Ohio Lung Association v. EPA, 572 F.2d 1143 (6th Cir.1978), we described how these latter determinations are to be made:

Scrutiny of the facts does not end, however, with the determination that the [administrative officer] has acted within the scope of his statutory authority. Section 706(2)(A) [of the Administrative Procedure Act] requires a finding that the actual choice made was not "arbitrary and capricious, an abuse of discretion, or otherwise not in accordance with law." 5 U.S.C. Sec. 706(2)(A) [1970]. To make this finding the court must consider whether the decision was based on a consideration of the relevant factors and whether there has been a clear error of judgment ...

... although this inquiry into the facts is to be searching and careful, the ultimate standard of review is a narrow one. The court is not empowered to substitute its judgment for that of the agency. (Emphasis in original.)

Id. at 1148, (quoting Buckeye Power, Inc. v. EPA, 481 F.2d 162, 171 (6th Cir.1973)). See also Cleveland Electric Illuminating Co. v. EPA, 572 F.2d 1150 (6th Cir.1978).

The petitioner nowhere contends that the rulemaking at issue was unconstitutional. However, Great Lakes Steel does raise a series of objections claiming, at various points, that the EPA has overstepped its statutory authority and/or has acted arbitrarily in its specific determinations.

The petitioner's first argument has several elements, all urging the conclusion that the EPA has overstepped its authority and acted arbitrarily in making its RACT determinations in this case.

* First, petitioner claims that, since fugitive dust significantly contributes to nonattainment, the EPA should not require stationary sources to install RACT before Michigan completes its own studies concerning the relationship between fugitive dust and nonattainment and the possible methods for controlling that particular pollutant. Great Lakes Steel contends that it is unreasonable to interpret the statute as requiring mandatory RACT absent proof that the imposition of the installation cost will in any way contribute to attainment.

The EPA interprets the Act to unambiguously require installation of RACT at a minimum on existing sources in the nonattainment areas. While the EPA does not deny that it has itself adopted an administrative exemption to this otherwise "mandatory" requirement, it views that exemption as being narrowly tailored to fit within, and further, the spirit and goals of the Act. On the contrary, the EPA feels that the exemption suggested by Great Lakes Steel, i.e., to wait and see what the state studies show before requiring RACT, would altogether vitiate the mandates of Sec. 172, thereby undercutting the purposes of the Act.

An agency's interpretation of the statute it has been created to implement is to be given considerable deference. U.S. v. City of Painesville, 644 F.2d 1186, 1190-91 (6th Cir.1981); ASARCO, Inc. v. EPA, 578 F.2d 319, 325 (D.C.Cir.1978). That interpretation need not be the only one the agency could have permissibly adopted in order to be acceptable; it need only be reasonable:

When different interpretations of the statute are plausible, so long as the EPA's construction of the statute is reasonable, we may not substitute our own interpretation for the agency's, Train v. NRDC, supra, 421 U.S. at 75 [95 S. Ct. 1470 at 1479, 43 L. Ed. 2d 731]. "The construction of a statute by those charged with its execution should be followed unless there are compelling indications that it is wrong." Red Lion Broadcasting Co. v. FCC, 395 U.S. 367, 381 [89 S. Ct. 1794, 1801, 23 L. Ed. 2d 371] (1967); accord, Beal v. Doe, 432 U.S. 438 [97 S. Ct. 2366, 53 L. Ed. 2d 464] (1977) ....

Lead Industries Ass'n., Inc. v. EPA, 647 F.2d 1130, 1147 (D.C.Cir.), cert. denied, 449 U.S. 1042, 101 S. Ct. 621, 66 L. Ed. 2d 503 (1980). As such, even if this Court were to view the petitioner's interpretation as reasonable, the Administrator's construction of the statute must be upheld unless that view is plainly unreasonable. Id. See also Train v. NRDC, 421 U.S. 60, 95 S. Ct. 1470, 43 L. Ed. 2d 731 (1975).

The point is well taken that an action which will clearly not further attainment should not be required. However, as noted previously, it is unclear to what extent each source of pollutants contributes to the nonattainment problem. All admit that the nature of the problem is too complex to allow for specific determinations of whether particular actions will or will not best further the attainment goal. It cannot be debated that RACT on existing stationary sources will ensure that those sources are not contributing to or exacerbating nonattainment. It does not appear unreasonable for Congress to have granted the EPA the power to act with regard to known, identifiable sources of particulate matter, even though they remain unable to quantify the precise degree to which those sources are preventing the attainment of the NAAQS.

Section 172(b)(3) of the Act specifically states that a SIP "shall ... require" RACT in the circumstances it defines. There is nothing in the statute which indicates that these terms are not to be given their plain meaning. In addition, we could find nothing in the legislative history of these provisions which in any way contradicts the mandatory character of the language employed. See S.Rep. No. 1196, 91st Cong., 2d Sess. 16 (1970), reprinted in Legislative History of the Clean Air Amendments of 1970 (Comm. Print 1974). In light of the wording, history and rationale of the statute and the complex nature of the problem facing the EPA, it does not appear that a realistic application of the Sec. 172 criteria could do anything less than require RACT for existing sources in nonattainment areas. At minimum, we clearly cannot say, as petitioner would have us, that EPA's interpretation of the Act is plainly unreasonable.

Second, Great Lakes Steel asserts that the EPA has essentially created its own uniform set of RACT standards, bearing no relation to the nonattainment problem in Michigan. They claim that the imposition of the EPA's own standards has improperly usurped the statutory role of the state. This, petitioner argues, is both arbitrary and, by analogy, "ultra vires". EPA counters that it has not adopted "uniform" RACT standards and that the information it has compiled has not been "imposed" upon the states. Instead, EPA argues that its data is merely a starting point for the states to develop RACT requirements and a guideline for EPA's general evaluation of a state's RACT proposals, given the economic and technical circumstances surrounding the particular sources being regulated.

The states are given wide discretion in formulating and revising their individual implementations plans. See Ohio Environmental Council v. United States, etc., 593 F.2d 24, 29 (6th Cir.1979); Northern Ohio Lung Association v. EPA, 572 F.2d 1143 (6th Cir.1978). They have the primary responsibility for attaining and maintaining air quality. The role of the EPA in this scheme is purely a secondary one. Train v. Natural Resources Defense Council, 421 U.S. 60, 95 S. Ct. 1470, 43 L. Ed. 2d 731 (1975). The issue then is whether the EPA's RACT determinations are consistent with that role. Cf. Ohio Environmental Council v. United States, etc., 593 F.2d at 29.

There is no doubt that the EPA is empowered to evaluate proposed RACT standards to some extent. While the state does have the primary responsibility for establishing RACT guidelines, the EPA's statutory obligation before approving a SIP is to ensure that RACT is actually provided for. See Sec. 110(a)(2)(I) of the Act in conjunction with Sec. 172(b)(3).12 The EPA claims that it only uses its RACT data as a guide in fulfilling this obligation. It cites a variety of EPA notices and regulations for the proposition that the EPA has not adopted inflexible standards. The EPA defines RACT as:

the lowest emission limitation that a particular source is capable of meeting by the application of control technology that is reasonably available considering technological and economic feasibility. Therefore, depending on site-specific considerations, such as geographic constraints, RACT can differ for similar sources.

45 Fed.Reg. 59331 (September 9, 1980) (emphasis added). The EPA claims that it will review and evaluate proposed standards on the basis of the state analysis, "taking into account all the available data as well as public comment on the state's analysis and the EPA's evaluation thereof." 45 Fed.Reg. 59199 (September 8, 1980).

This picture of flexibility is drawn into question, however, when one considers the practical application of these standards. While the EPA indicates that it only requires a state to make a threshold offering of information on which an evaluation can be based, it does seem to establish a presumption, albeit rebuttable, that its own data defines RACT. Consider EPA Statement at 45 Fed.Reg. 59331 (September 9, 1980):

USEPA believes that the burden of demonstrating that a regulation represents RACT rests on the state. In reviewing a proposed SIP revision to determine its adequacy, USEPA can verify independently that the provisions in the state plan represent RACT. Although USEPA has not specified uniform RACT standards for the iron and steel industry, it has collected data which reflects the emission limitations achieved by various iron and steel sources applying control technology .... Where a state proposed regulations which are not technically supported by US EPA's data, the state must submit adequate data supporting its proposal as representing RACT.

The EPA is not required to accept a state's data without undertaking a critical evaluation of it. The accumulation of an alternative database would seem to be a necessary framework for such an evaluation. The formulation of a presumption against the acceptability of state standards appears troublesome, however. By placing such an additional burden on the states, the EPA seems to be removing some of the flexibility that Congress meant to afford the states in formulating their individual implementation plans. This may, indeed, be beyond the bounds of the discretion which the EPA is permitted to exercise in fulfilling its secondary role. We need not, however, nor do we choose to, resolve that issue in the case before us. In the circumstances presented, we consider the EPA's use of its own data for making its RACT determinations to be in keeping with its statutory role. Reason dictates that the EPA must have some basis from which to evaluate proposed SIPs; "approval" absent data to consider would be no more than rubber-stamping. The EPA can only be in a position to fulfill its statutory obligations if it has some degree of expertise, or some way of getting that expertise, regarding RACT in each relevant industry. In the instant case, Michigan did not supply detailed information in support of its RACT determinations. Where a state fails to supply the information necessary for a proper evaluation by the EPA, the EPA must be free to use its own acquired knowledge. In such circumstances, we readily find that the EPA has neither overstepped the bounds of its authority nor acted unreasonably.

The petitioner argues in the alternative that, assuming arguendo that the EPA may impose its own RACT standards on Michigan, the standards imposed were unreasonable. This argument has two branches. First, Great Lakes Steel claims that imposition of a RACT requirement on a given source without showing how that source contributes to nonattainment is unreasonable. Second, it contends that the technical standards set were unreasonable in light of the state of the iron and steel industry in Michigan.

The first argument is essentially a reiteration of that raised with regard to the imposition of any RACT standard, and can be dealt with similarly. The fact that there is insufficient technical knowledge to determine the precise degree to which each source contributes to nonattainment does not require that the EPA be prohibited from acting with regard to all sources. There is no doubt that iron and steel sources emit harmful particulate matter into the ambient air. Michigan could have avoided RACT requirements for these stationary sources by otherwise demonstrating attainment "as expeditiously as practicable." Michigan did not, or could not, do so with regard to these nonattainment areas. We find that it is wholly consistent with the scheme of the Act to place the burden on the state to show that RACT on its iron and steel sources is not necessary.

The second argument is aimed at the particular EPA-imposed limitations. Great Lakes Steel contends that it was unreasonable to disapprove the state emission limitations for blast furnaces, heating and reheating furnaces, and sinter plants and to insist on the conditions chosen for approval of the other iron and steel emission regulations.

The EPA disapproved the furnace and sinter plant limitations outright because its technical data indicated that more stringent air quality controls were achievable. Great Lakes Steel's objection to these rulings is essentially grounded upon claims of technological and economic infeasibility. Great Lakes Steel argues as follows: (1) the blast furnace standards are nonattainable because it is technologically infeasible to retrofit the necessary controls onto the existing cast houses; (2) the heating and reheating furnace limitations are unreasonable because the de minimus level of emissions from these sources does not justify the cost of further controls; and (3) the sinter plant standards are unreasonable because they would require the replacement of a newly-installed, costly control system.

The Supreme Court has held that neither the Administrator nor a reviewing court may reject a SIP on the ground that it is economically or technologically infeasible. Union Electric Co. v. EPA, 427 U.S. 246, 265, 96 S. Ct. 2518, 2529, 49 L. Ed. 2d 474 (1976). This Court has expressed "genuine doubt" that a court of appeals ever has the power to consider infeasibility objections to an implementation plan, even where the plan is EPA-designed.13 Cleveland Electric Illuminating Company v. EPA, 572 F.2d 1150, 1164 (6th Cir.1978). We are confident in concluding that it is at least inappropriate for the Administrator or this Court to approve state proposed limitations purely on the basis of such considerations. See South Terminal Corporation, etc. v. EPA, etc., 504 F.2d 646, 656 (1st Cir.1974).

Congress set minimum standards for acceptable air quality. If a SIP or Part D revision fails to meet those standards it cannot be approved. Congress clearly recognized the possibility that these requirements may appear infeasible to those sources on whom they would be imposed.14 That fact however, was not deemed a sufficient justification for failing to impose even the strictest of standards:

In the Committee discussions, considerable concern was expressed regarding use of the concept of technical feasibility as the basis of ambient air standards. The Committee determined that 1) the health of people is more important than the question of whether the early achievement of ambient air quality standards protective of health is technically feasible; and 2) the growth of pollution load in many areas, even with application of available technology, would still be deleterious to public health. Therefore, the Committee determined that existing sources of pollutants either should meet the standard of the law or be closed down....

Union Electric Co. v. EPA, supra, 427 U.S. at 259, 96 S. Ct. at 2526 (quoting S.Rep. No. 91-1196, pp. 2-3 (1970)). The Supreme Court has recognized the "technology-forcing character" of the requirements of the Clean Air Act and, as such, has concluded that the Act was "expressly designed to force regulated sources to develop pollution control devices that might at the time appear to be economically or technologically infeasible." Id. at 257, 96 S.Ct. at 2525. See also Train v. NRDC, 421 U.S. at 91, 95 S.Ct. at 1487.

We agree with the First Circuit's statement in South Terminal Corporation, etc. v. EPA, 504 F.2d at 656, that:

... neither the EPA nor this Court has any right to decide that it is better to maintain pollutants at a level hazardous to health than to require the degree of public sacrifice needed to reduce them to tolerable limits.

Our prior decisions have reflected an awareness of both the high cost of attaining acceptable air quality standards and of the conscious decision of Congress to impose those costs. See U.S. v. City of Painesville, 644 F.2d at 1192; Cleveland Electric Illuminating Co. v. EPA, 572 F.2d at 1164. Accordingly, we find Great Lakes Steel's infeasibility arguments unpersuasive.15

The remainder of the petitioner's complaints are aimed at the EPA's conditional approval of the regulations designed to control emissions generated by coke oven pushing, standpipe assemblies, quenching towers and the scarfing process. Great Lakes Steel claims that the clarifications and/or changes, upon which approval of these state regulations were conditioned, are unreasonable.

As noted, we are required to affirm agency determinations unless we find that they are "arbitrary and capricious" and we can only make that determination where the EPA has failed to consider the relevant factors for determination or has made a clear error of judgment. See Citizens to Preserve Overton Park v. Volpe, 401 U.S. at 416, 91 S.Ct. at 823. We find on the record before us that the EPA's particular conditions for approval represent reasonable methods for dealing with legitimate concerns regarding the effectiveness and enforceability of Michigan's iron and steel emissions regulations. As such, we find no basis for failing to affirm the choice of those conditions.16

In sum, we find that the EPA's final rulemaking with regard to Michigan's Part D SIP revisions was wholly within the bounds of its statutory authority and was neither arbitrary and capricious, nor otherwise not in accordance with law. Accordingly, we affirm that rulemaking in all respects.